Context

PR 1507 (tentatively) removes the need to calculate 90th percentile and standard deviation for RTT samples. Those are the last two "production" use cases for the "github.com/montanaflynn/stats" package in the Go driver. We should remove all other uses of the "stats" package so we can remove it from the Go driver dependencies.

Definition of done

• Remove the "github.com/montanaflynn/stats" dependency from the Go driver module.
• Make the benchmark system its own submodule so it can pull in additional dependencies (similar to the awslambda/mongodb module).
• Optional: Consider moving the internal/benchmark code into internal/cmd/benchmark since that's the only place it's used.

Pitfalls